From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22AB5C433E0 for ; Mon, 22 Mar 2021 12:35:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EAA50619A2 for ; Mon, 22 Mar 2021 12:35:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231183AbhCVMeo (ORCPT ); Mon, 22 Mar 2021 08:34:44 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:37613 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230376AbhCVMdn (ORCPT ); Mon, 22 Mar 2021 08:33:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616416422; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=6YlEy3IX1gunaw091y2xQmF4LKXF/jaek9xmyTD34qw=; b=WdRAMHI+jHok6jjKSUmf3vaSgC84rzKKodmMpagK6P8/Ew4gHEbr1/aSannCkon0l63p0l fwPSG6NL5fY+JJhWr5SwIJLPIZ+9IDrLoEOj/ZBHx0ve24gujk9E/KAP5uOwSBAB5BvFzU INk46XOp5Fv20/siNm74Tp1pGl+buZA= Received: from mail-pl1-f197.google.com (mail-pl1-f197.google.com [209.85.214.197]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-386-MytiEOA1N8mJTqPWsIO0Ug-1; Mon, 22 Mar 2021 08:33:41 -0400 X-MC-Unique: MytiEOA1N8mJTqPWsIO0Ug-1 Received: by mail-pl1-f197.google.com with SMTP id u5so24116488plg.2 for ; Mon, 22 Mar 2021 05:33:40 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=6YlEy3IX1gunaw091y2xQmF4LKXF/jaek9xmyTD34qw=; b=Og/iFKelDKHLS62Hy8mfX94eb8cTVbiMYEWSzIkLHUdEClKqIO0Lnh6ikOcev5wk24 HlBTZZplNEOYp+xTDK/lqn2lhWeRlT27gnv/luUMsFyiqXH51xlzjmyufKd1RwtoNl0E aEuNxwVqWOrgH9kprsJQl6ReoTTNGTIIgxQHn8wsOnQ0TKladlOGUQN2N1DMyM1vZ1+A Rc7t17t72A0h7scv5+ShNHzbdiqu53Ewj+NGJ89FGlsRFLomNGNANU2oJufpry785pY/ ufKQA4AFXZ/UW03rFpjVhXCEkHTXQB2Labc8my449Z4L1FmU6S4LUKImhCTPV3O3LPOr sirw== X-Gm-Message-State: AOAM533/vKAwoNxFnAop5seIiBFseoGnKBCl9z1AQA8JgDfHMnnoCH9/ WYGRZtba3A2TPZusxQAZOlCkF9zaEW3z2W4lrNG06ggAQfsKnCUkoZsH40ahCxesKgLz0hVN7ot I9sz5+Py1fTD6jkjlppYB X-Received: by 2002:a17:90a:c201:: with SMTP id e1mr13172203pjt.30.1616416419495; Mon, 22 Mar 2021 05:33:39 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyOiU8Dl+6xnIHyGRha4RNUlwKS0GImcXQ294giOuhUOA0xKZMBsOu2Bn7w44/I2cHtDLsyKA== X-Received: by 2002:a17:90a:c201:: with SMTP id e1mr13172187pjt.30.1616416419302; Mon, 22 Mar 2021 05:33:39 -0700 (PDT) Received: from xiangao.remote.csb ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id f20sm13990503pfa.10.2021.03.22.05.33.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Mar 2021 05:33:38 -0700 (PDT) Date: Mon, 22 Mar 2021 20:33:28 +0800 From: Gao Xiang To: Brian Foster Cc: linux-xfs@vger.kernel.org, "Darrick J. Wong" , Dave Chinner , Christoph Hellwig , Eric Sandeen Subject: Re: [PATCH v8 3/5] xfs: introduce xfs_ag_shrink_space() Message-ID: <20210322123328.GA2007006@xiangao.remote.csb> References: <20210305025703.3069469-1-hsiangkao@redhat.com> <20210305025703.3069469-4-hsiangkao@redhat.com> <20210322120310.GB2000812@xiangao.remote.csb> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Mon, Mar 22, 2021 at 08:25:55AM -0400, Brian Foster wrote: > On Mon, Mar 22, 2021 at 08:03:10PM +0800, Gao Xiang wrote: > > Hi Brian, > > > > On Mon, Mar 22, 2021 at 07:30:03AM -0400, Brian Foster wrote: > > > On Fri, Mar 05, 2021 at 10:57:01AM +0800, Gao Xiang wrote: > > > > This patch introduces a helper to shrink unused space in the last AG > > > > by fixing up the freespace btree. > > > > > > > > Also make sure that the per-AG reservation works under the new AG > > > > size. If such per-AG reservation or extent allocation fails, roll > > > > the transaction so the new transaction could cancel without any side > > > > effects. > > > > > > > > Signed-off-by: Gao Xiang > > > > --- > > > > > > Looks mostly good to me. Some nits.. > > > > > > > fs/xfs/libxfs/xfs_ag.c | 111 +++++++++++++++++++++++++++++++++++++++++ > > > > fs/xfs/libxfs/xfs_ag.h | 4 +- > > > > 2 files changed, 114 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/fs/xfs/libxfs/xfs_ag.c b/fs/xfs/libxfs/xfs_ag.c > > > > index 9331f3516afa..1f6f9e70e1cb 100644 > > > > --- a/fs/xfs/libxfs/xfs_ag.c > > > > +++ b/fs/xfs/libxfs/xfs_ag.c > > > ... > > > > @@ -485,6 +490,112 @@ xfs_ag_init_headers( > > > > return error; > > > > } > > > > > > > > +int > > > > +xfs_ag_shrink_space( > > > > + struct xfs_mount *mp, > > > > + struct xfs_trans **tpp, > > > > + xfs_agnumber_t agno, > > > > + xfs_extlen_t delta) > > > > +{ > > > > + struct xfs_alloc_arg args = { > > > > + .tp = *tpp, > > > > + .mp = mp, > > > > + .type = XFS_ALLOCTYPE_THIS_BNO, > > > > + .minlen = delta, > > > > + .maxlen = delta, > > > > + .oinfo = XFS_RMAP_OINFO_SKIP_UPDATE, > > > > + .resv = XFS_AG_RESV_NONE, > > > > + .prod = 1 > > > > + }; > > > > + struct xfs_buf *agibp, *agfbp; > > > > + struct xfs_agi *agi; > > > > + struct xfs_agf *agf; > > > > + int error, err2; > > > > + > > > > + ASSERT(agno == mp->m_sb.sb_agcount - 1); > > > > + error = xfs_ialloc_read_agi(mp, *tpp, agno, &agibp); > > > > + if (error) > > > > + return error; > > > > + > > > > + agi = agibp->b_addr; > > > > + > > > > + error = xfs_alloc_read_agf(mp, *tpp, agno, 0, &agfbp); > > > > + if (error) > > > > + return error; > > > > + > > > > + agf = agfbp->b_addr; > > > > + if (XFS_IS_CORRUPT(mp, agf->agf_length != agi->agi_length)) > > > > + return -EFSCORRUPTED; > > > > > > Is this check here for a reason? It seems a bit random, so I wonder if > > > we should just leave the extra verification to buffer verifiers. > > > > It came from Darrick's thought. I'm fine with either way, but I feel > > confused if different conflict opinions here: > > https://lore.kernel.org/linux-xfs/20210303181931.GB3419940@magnolia/ > > > > Darrick's comment seems to refer to the check below. I'm referring to > the check above that agi_length and agf_length match. Are they intended > to go together? The check above seems to preexist the one below. Sorry, update link of this: https://lore.kernel.org/r/20210111181753.GC1164246@magnolia/ > > Anyways, if so, maybe just bunch them together and add a comment: > > /* some extra paranoid checks before we shrink the ag */ > if (XFS_IS_CORRUPT(...)) > return -EFSCORRUPTED; > if (delta >= agf->agf_length) > return -EVINAL; > ok, will update this. > > > > > > > + > > > > + if (delta >= agi->agi_length) > > > > + return -EINVAL; > > > > + > > > > + args.fsbno = XFS_AGB_TO_FSB(mp, agno, > > > > + be32_to_cpu(agi->agi_length) - delta); > > > > + > > > > + /* remove the preallocations before allocation and re-establish then */ > ... > > > > diff --git a/fs/xfs/libxfs/xfs_ag.h b/fs/xfs/libxfs/xfs_ag.h > > > > index 5166322807e7..41293ebde8da 100644 > > > > --- a/fs/xfs/libxfs/xfs_ag.h > > > > +++ b/fs/xfs/libxfs/xfs_ag.h > > > > @@ -24,8 +24,10 @@ struct aghdr_init_data { > > > > }; > > > > > > > > int xfs_ag_init_headers(struct xfs_mount *mp, struct aghdr_init_data *id); > > > > +int xfs_ag_shrink_space(struct xfs_mount *mp, struct xfs_trans **tpp, > > > > + xfs_agnumber_t agno, xfs_extlen_t len); > > > > int xfs_ag_extend_space(struct xfs_mount *mp, struct xfs_trans *tp, > > > > - struct aghdr_init_data *id, xfs_extlen_t len); > > > > + struct aghdr_init_data *id, xfs_extlen_t delta); > > > > > > This looks misplaced..? > > > > > > Or maybe this is trying to make the APIs consistent, but the function > > > definition still uses len as well as the declaration for > > > _ag_shrink_space() (while the definition of that function uses delta). > > > > > > FWIW, the name delta tends to suggest a signed value to me based on our > > > pattern of usage, whereas here it seems like these helpers always want a > > > positive value (i.e. a length). > > > > Yeah, it's just misplaced, thanks for pointing out, sorry about that. > > `delta' name came from, `len' is confusing to Darrick. > > https://lore.kernel.org/r/20210303182527.GC3419940@magnolia/ > > > > Fair enough. I'm not worried about the name, just pointing out some > potential inconsistencies. Thanks for pointing out! Thanks, Gao Xiang > > Brian > > > Thanks, > > Gao Xiang > > > > > > > > Brian > > > > > > > int xfs_ag_get_geometry(struct xfs_mount *mp, xfs_agnumber_t agno, > > > > struct xfs_ag_geometry *ageo); > > > > > > > > -- > > > > 2.27.0 > > > > > > > > > >